Ice covered surfaces are treacherous for foot, vehicular and ground aircraft traffic. The use of traction-increasing particulate, such as sand or grit, or ice-melting materials, such as salt or chemicals, is disadvantageous due to cost, storage, and potential for environmental damage, as well as damage to engines with which these materials come in contact. Service data shows that aircraft which operate out of airports in northern climate regions which use winter time sanding suffer accelerated deterioration rates. Engine teardowns show that sand erosion is the primary cause of wintertime performance deterioration, including such problems as eroded fan and compressor airfoil and eroded blade tip seals. Technology trends dictate that sand ingestion must be reduced in the future.
Although a variety of mechanical devices have been suggested for abrading icy surfaces, the present invention provides the convenience of using conventional, readily available rotary-type power lawn mowers. Other attachments for facilitating use of lawn mowers, other than for their normal grass-cutting operation, have been suggested, but none offer the specific features and advantages of the present invention.
Draughon, U.S. Pat. No. 2,863,162, discloses a conventional lawn mower which includes a horizontally rotatable blade transformable to a snow sweeper by application of brushes over the ends thereof. As described therein, this device would simply not provide the abrasive action necessary for increasing traction on icy surfaces.
Erickson, U.S. Pat. No. 2,983,057, discloses a blower head attachment for converting a conventional rotary lawn mover into a snow removal machine. The attachment is a blower head at the forward end thereof with an upright plate having a front blower or pusher face. Again, this device provides snow removal only, without providing increased traction on icy surfaces.
Stoddard, U.S. Pat. No. 2,984,919, discloses a snow removal attachment for a conventional rotary lawn mower with a special rotary support which uses a blower rather than conventional fan action. Here also, no provision is made for increasing traction on icy surfaces.
Beckner, U.S. Pat. No. 3,775,878, describes a snow removal attachment device for rotary-type mowers. The attachment device is a resilient, snow-engaging wiper-type member inclined at an angle rearwardly away from the direction of rotation, so that the trailing end wipes against the ground surface while resiliently avoiding rocks and surface irregularities. This device also is not suitable for improving traction on icy surfaces.
Blackstone, U.S. Pat. No. 4,409,781 describes a thatching tool for attachment to a rotary lawn mower. The tool includes a rotatable supporting bar to be rotated by a motor of the mower with the bar having thatching teeth mounted at both ends. Although this device bears some similarity to the ice scarifying attachment of the present invention, it does not offer the particular design and materials necessary for extended, rigorous use on demanding ice covered surfaces.
Bokon, U.S. Pat. No. 4,719,743, describes a lawn mower which can also function as a winter snow thrower. To function as a snow thrower, a sprocket chain is replaced by a gear train to connect the gear box to the sprocket. A short sheet metal ramp is added which scoops up the snow and lifts it to the level of the transverse cutting bar to direct the scooped snow into the cutting zone of the rotary cutter assembly. The rotary cutter assembly loosens the snow and the blower discharges the snow away from the path of the machine. This device is not adapted for improving traction on ice covered traffic surfaces.